/*
 * @Author: chentao 
 * @Date: 2022-05-05 10:45:01 
 * @Last Modified by: chentao
 * @Last Modified time: 2022-05-07 17:24:50
 */
const mixArr:(string|number)[]=[];
mixArr.push("nameString");
mixArr.push(22);
mixArr.forEach((value,index,arr)=>{
     console.log(`遍历item ${value}->${index}->${arr}`);
})
//输出
/**
 * 遍历item nameString->0->nameString,22
  遍历item 22->1->nameString,22

 */
let obj ;
obj?.name; //得把严格模式关闭掉为false表示关闭 "strict": false, 
console.log(`输出obj.name:${obj?.name}`);
obj = new Object();
obj.name="lisi";
console.log(`输出obj.name2:${obj?.name}`);
const un:undefined = undefined;
const nu:null = null;
console.log(`undefined ${un}`)
console.log(`null ${nu}`)
